Official - penguins don't topple over

Good news for king penguins: the Royal Navy mission sent to Antarctica to investigate whether they fall on their backs when aircraft pass overhead has completed its rigorous experiments.

For five weeks scientists filmed the earthbound birds' reactions as they peered up at Lynx helicopters from HMS Endurance criss-crossing the skies above the island of South Georgia at heights of between 1,500ft and 6,000ft.

Would the unbalanced penguins, as veteran Falklands war pilots claimed, be so mesmerised that they would swivel round, craning their necks and topple over? Sadly, for those attached to the popular myth, king penguins are more level-headed than was previously assumed.

"We saw birds moving away from the noise," said Dr Richard Stone, of the British Antarctic Survey. "Not a single bird fell over after 17 flights. As it [the helicopter] approached, the birds went quiet. They didn't appear to turn around and look."

He did notice some penguins waddling away from the helicopters. Others became quiet, but a few minutes later, they waddled back. "We don't know if it's the noise or the visual aspect - whether it looks like a potential predator," Dr Stone said.

His findings are a relief for countries which operate aircraft in the southern Atlantic and Antarctica: they are less likely now to come under pressure from environmentalists to change flight patterns. King penguins, the second biggest penguin in the world, weigh 35kg and are about a metre tall.

The survey may not convince pilots who served in the South Atlantic in 1982, who first claimed to have seen the phenomenon, nicknamed "penguin topple". Stuart Matthews, an operations officer on board Endurance, said last year: "The penguins always look up at the helicopters flying over and follow them all the way until they fall over backwards."

The survey team is planning a second set of experiments using fixed-wing aircraft.